SSE has reported a 19.3% drop in full-year pre-tax profits to £593.3 million after lower energy prices and increased competition took their toll on the firm.
The company, one of the country's largest energy suppliers, was hit hardest at its wholesale business, which saw adjusted operating profit drop 6.6% to £442.5 million. Profits at its gas production arm fell 94% to £2.2 million.
Chief executive Alistair Phillips-Davies said: "The operating environment presented a number of complex issues, including the impact of prevailing commodity prices and intense retail market competition. At the same time, SSE has continued to demonstrate financial discipline and commitment to its long-term strategic framework."
SSE, which lowered energy prices for its 8.5 million customers in January, said retail operating profit was broadly flat at £455.2 million.
On an adjusted basis, pre-tax profit was down 3.3% to £1.5 billion across the company.
Mr Phillips-Davies added: "The fact that some of the mist is beginning to clear around the legislative, political and regulatory environment means there are grounds for some cautious optimism for the next couple of years."